There are many forms of container washers in which the objective is to receive containers in a haphazard condition and to thoroughly clean and sterilize the internal surfaces as well as to completely remove neck and body labels so that the containers delivered at the discharge of the washers are in a sterile, clean and bright condition. One of the problems in container washers is concerned with the removal of the labels with as much delicacy as possible so as to reduce the amount of shredding and pulping of the labels, thereby reducing the contamination of the hot caustic solution which is generally utilized to effect the cleaning and sterilizing of the containers as well as to attack the adhesive utilized for affixing the labels.
In one form of container washer which is illustrated in Winters U.S. Pat. No. 2,710,818 of June 14, 1955, the apparatus is designed to produce pulping of the labels internally of the washer, followed by delivery of the pulp contaminated caustic solution to external settling tanks before returning the decanted solution to the washer. The problem with this approach resides in the excessive contamination of the caustic solution and the need to allow sufficient settling time for the pulp.
Another approach to apparatus for removing labels from container washers is disclosed is Babunovic et al U.S. Pat. No. 3,162,204 of Dec. 22, 1964. In this apparatus the accumulation of labels within the washer is maintained at a minimum by constantialy jetting the labels into an external system where the labels are forcibly extracted from the washing solution before the solution is returned to the washer. The extraction of the labels from the washing solution is quite efficient but it is necessary to limit the number of compartments in the washer that can be serviced at one time.
A more recent arrangement for removing labels from container washing solution is found in Cove et al U.S. Pat. No. 3,868,960 of Mar. 4, 1975 where the solution burdened with labels is delivered by the difference in hydrostatic levels to an external tank in which a rotating screen lifts the labels out of the washing solution to an elevated position where the labels can be removed from the rotating screen and directed out of the tank above the level of the washing solution so as to clear the solution from carrying labels back to the washer and the suction out of the external tank.